In the world of go-cart racing one-hundred mile races are won, and lost, by mere inches. Naturally, with margins this narrow, any advantage is important and, although engine displacement and other performance-related parameters are tightly regulated, some performance-enhancing adjustments are permitted. For example, racers may change tires during a race to match driving conditions. As a result, soft rubber tires are typically used on a cold track to improve traction, while harder tires, which reduce rolling resistance and permit higher speeds, are used on a warmer track.
Additionally, one may adjust the exhaust system of a cart to enhance performance; a long exhaust pipe yields more revolutions per minute (RPMs) at the expense of lower torque. This trade-off would be advantageous on a long track, where a lower percentage of time is spent in the corners than on a short track. Conversely, a short exhaust pipe would be desirable for operation on a short track.
Rather than hauling exhaust pipes of various lengths from race track to race track, racers generally adjust their exhaust system's length before a race by inserting an appropriate length of exhaust pipe between the header pipe of the engine and the tail pipe. Using this approach, racers may tone adjust the performance of their cart depending upon the length of the track they will be racing on.
However, certain other factors, such as barometric pressure, also affect performance and they too can be accommodated by adjusting the length of the exhaust system. Because such environmental conditions may change immediately before, or even during a race, it is difficult if not impossible to determine the most advantageous length of pipe to use. Therefore, racers typically adjust the exhaust systems by replacing the exhaust pipe insert during a race with one that is longer or shorter, depending upon what change (e.g., greater torque or greater RPMs) is desired.
Unfortunately, to change an exhaust system pipe section is both a time-consuming and hazardous task. All the parts being replaced are extremely hot, yet bolts, clamps and a section of pipe must be removed and replaced. Although the mechanics who replace the pipe sections typically protect their hands with gloves, the gloves diminish their dexterity, thus slowing the operation. And even though the gloves are heavy and insulated mechanics nonetheless often sustain severe burns.